This invention relates to a golf club head. More particularly, the invention relates to a golf club head with an insert integrally bonded to the club face wherein the insert comprises an extremely hard and durable surface for contacting the ball and efficiently transferring energy thereto.
Designers of golf equipment have long sought after an optimum design of golf clubs and balls, both in terms of physical design and selection of materials, for achieving maximum performance. There have been numerous efforts to arrive at innovative designs of club heads, club head materials, and shaft materials for maximum performance, i.e. distance that the ball is propelled after being struck.
Traditionally, woods (clubs usually used for tee shots and longer fairway shots) have heads made of hard wood, the preferred wood being persimmon. The tendency of wood to warp or split, however, coupled with increasing costs of material and labor, has led to development of woods fabricated of materials other than wood. For example, there are many different kinds of engineered materials currently being used in the construction of the club head or club face, such as steels, cast irons, aluminum, copper, titanium, graphite, plastics, woods, and carbides and their alloys and composites. For example, there is a club referred to as an "insert in metal head," wherein the head of the club is made of metal with a full face graphite insert, commercially available as "THUNDER HEAD WOOD" from Spalding, or an engineered plastic insert, commercially available as "ODYSSEY." G. Rennie, U.S. Pat. No. 5,362,055, describes a "metal wood" wherein the club head is molded or formed in substantially one piece, but a nonmetallic insert is secured to a cavity formed in the ball striking face. P. Niskanen et al., U.S. Pat. No. 5,342,812, disclose golf club heads that utilize composite materials, such as metal matrix composite and/or ceramic matrix composite materials, for the body, face, and/or sole of the club head.
D. Kim, U.S. Pat. Nos. 4,951,953 and 5,029,865, states the desirability of using rigid materials, i.e. materials with a high "Young's Modulus," in golf clubs such that the distance travelled by the ball is increased. Kim discloses golf clubs wherein the head, shaft, or both are coated with such materials. A particularly preferred material is a diamond-containing coating, because diamond is the hardest material known and has the highest Young's Modulus. Kim recognizes that a coating of pure diamond would be ideal, but states that such coatings are difficult and costly to apply, and the pure diamond material is itself costly. Therefore, Kim teaches coatings of 10-100 .mu.m electroless composite material wherein diamond particles are embedded in a metal or metal alloy matrix, such as a nickel matrix, such that the diamond particles are weakly cemented together by the soft metal without any diamond-diamond bonds.
In view of the foregoing, it will be appreciated that providing a golf club head comprising an insert in the ball striking face, wherein the insert comprises a compact such that particles of material having a high Young's Modulus are bonded to each other, would be a significant advancement in the art.